From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0466C43462 for ; Sun, 2 May 2021 06:31:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5FF5E6054E for ; Sun, 2 May 2021 06:31:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5FF5E6054E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D13B06B006C; Sun, 2 May 2021 02:31:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CB2476B006E; Sun, 2 May 2021 02:31:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B528F6B0070; Sun, 2 May 2021 02:31:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0134.hostedemail.com [216.40.44.134]) by kanga.kvack.org (Postfix) with ESMTP id 975BA6B006C for ; Sun, 2 May 2021 02:31:35 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 4C4E02C7C for ; Sun, 2 May 2021 06:31:35 +0000 (UTC) X-FDA: 78095319750.12.7106656 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf06.hostedemail.com (Postfix) with ESMTP id 1CB65C0007CE for ; Sun, 2 May 2021 06:31:37 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 622FB6134F; Sun, 2 May 2021 06:31:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619937093; bh=SUTF4qHvvsvOCxRaO7XMs9cQTJeY156G3PPBU4Gks2Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SOUpNoydb/Dr01KO8+naCCL9W/VNTnBaeUOGgAEKVeY9Ki8wwSN/8gQXKYt4Eejj9 5ODj0fMX/fFoQnrlDWf0DIuyNGXeU1B5VzF9LMwxHZvEJ1+jVEHYmegGhZQdSqqiQT 2ElXY9X/fhAd0ms8gpUWE1EGsl7CF7uNmtg6MVqQFqTTLjG3BmSYNwDRoUlOQRKwsM /iHufKPwlGmiUSK1jvdTa0yM/xMbUgA6M1PZCE9EDYujnE/iBkj6SsVbqbz8pbkeSe +rB0HbrVWvKcCyAEeRj+m4of7Ad3w2qUphuxf/+YhkT5sygsX45ePs3e9C7cDv9Zn3 HCmDkz5w5Tw2A== Date: Sun, 2 May 2021 09:31:21 +0300 From: Mike Rapoport To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, Andrew Morton , "Michael S. Tsirkin" , Jason Wang , Alexey Dobriyan , "Matthew Wilcox (Oracle)" , Oscar Salvador , Michal Hocko , Roman Gushchin , Alex Shi , Steven Price , Mike Kravetz , Aili Yao , Jiri Bohac , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , Naoya Horiguchi , linux-hyperv@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v1 2/7] fs/proc/kcore: pfn_is_ram check only applies to KCORE_RAM Message-ID: References: <20210429122519.15183-1-david@redhat.com> <20210429122519.15183-3-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210429122519.15183-3-david@redhat.com> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 1CB65C0007CE Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=SOUpNoyd; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf06.hostedemail.com: domain of rppt@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=rppt@kernel.org X-Stat-Signature: numnbcrdqsmdbptzf7okatyxsm58ezgm Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf06; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1619937097-781909 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Apr 29, 2021 at 02:25:14PM +0200, David Hildenbrand wrote: > Let's resturcture the code, using switch-case, and checking pfn_is_ram() > only when we are dealing with KCORE_RAM. > > Signed-off-by: David Hildenbrand Reviewed-by: Mike Rapoport > --- > fs/proc/kcore.c | 35 +++++++++++++++++++++++++++-------- > 1 file changed, 27 insertions(+), 8 deletions(-) > > diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c > index 09f77d3c6e15..ed6fbb3bd50c 100644 > --- a/fs/proc/kcore.c > +++ b/fs/proc/kcore.c > @@ -483,25 +483,36 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) > goto out; > } > m = NULL; /* skip the list anchor */ > - } else if (!pfn_is_ram(__pa(start) >> PAGE_SHIFT)) { > - if (clear_user(buffer, tsz)) { > - ret = -EFAULT; > - goto out; > - } > - } else if (m->type == KCORE_VMALLOC) { > + goto skip; > + } > + > + switch (m->type) { > + case KCORE_VMALLOC: > vread(buf, (char *)start, tsz); > /* we have to zero-fill user buffer even if no read */ > if (copy_to_user(buffer, buf, tsz)) { > ret = -EFAULT; > goto out; > } > - } else if (m->type == KCORE_USER) { > + break; > + case KCORE_USER: > /* User page is handled prior to normal kernel page: */ > if (copy_to_user(buffer, (char *)start, tsz)) { > ret = -EFAULT; > goto out; > } > - } else { > + break; > + case KCORE_RAM: > + if (!pfn_is_ram(__pa(start) >> PAGE_SHIFT)) { > + if (clear_user(buffer, tsz)) { > + ret = -EFAULT; > + goto out; > + } > + break; > + } > + fallthrough; > + case KCORE_VMEMMAP: > + case KCORE_TEXT: > if (kern_addr_valid(start)) { > /* > * Using bounce buffer to bypass the > @@ -525,7 +536,15 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) > goto out; > } > } > + break; > + default: > + pr_warn_once("Unhandled KCORE type: %d\n", m->type); > + if (clear_user(buffer, tsz)) { > + ret = -EFAULT; > + goto out; > + } > } > +skip: > buflen -= tsz; > *fpos += tsz; > buffer += tsz; > -- > 2.30.2 > -- Sincerely yours, Mike.